CP, T and CPT violation in future long baseline experiments

I give a short overview about the possibilities and problems related to the measurement of CP violation in long baseline experiments. Special attention is paid to the issue of degeneracies and a method for their resolution is quantitatively discussed. The CP violation reach for different experiments is compared in dependence of $\sin^22\theta_{13}$ and \dm{21}. Furthermore a short comment about the possible effects of matter induced T violation is made. Finally the limits on CPT violation obtainable at a neutrino factory are shown.Comment: Talk presented at NUFACT02, London, 1-6 July, 2002. 3 pages, 2 figure

The functionalization of carbon nanotubes using a batch oscillatory flow reactor

This paper describes an efficient method for the functionalizing of multi-walled carbon nanotubes (MWCNT) using oscillatory flow mixing (OFM). A 3. l batch oscillatory flow reactor (OFR) was designed and constructed for pilot scale functionalization of MWCNT in order to potentially improve their compatibility within a thermoplastic polyphenylene sulphide (PPS) matrix. The OFM batch reactor consisted of a jacketed cylindrical vessel with a vertical axial oscillator that contained a series of baffled mixing plates. MWCNTs dispersed in dimethylformamide (DMF) were introduced into the reactor and a two stage reaction for functionalizing MWCNTs with PPS compatible groups was carried out under oscillation of baffles at elevated temperatures. Fluid mixing observations in the reactor showed that MWCNTs formed a uniform dispersion of aggregated flocs before and during the functionalization reaction. On completion of the reaction and cessation of the oscillation, the aggregated flocs of MWCNT rapidly sedimented at the bottom of the reactor; hence could be collected as a concentrated mass thereby facilitating the separation of functionalized MWCNTs from the solvent. The functionalized MWCNTs were dried and then characterized by transmission electron microscopy, infrared spectroscopy as well as thermal gravimetric analysis in order to investigate the extent of MWCNT functionalization. The characterization results confirmed the effective and relatively uniform functionalization of the MWCNTs despite formation of aggregates, indicating that OFM provides a viable approach for functionalizing MWCNTs

Algebraic structure of stochastic expansions and efficient simulation

We investigate the algebraic structure underlying the stochastic Taylor solution expansion for stochastic differential systems.Our motivation is to construct efficient integrators. These are approximations that generate strong numerical integration schemes that are more accurate than the corresponding stochastic Taylor approximation, independent of the governing vector fields and to all orders. The sinhlog integrator introduced by Malham & Wiese (2009) is one example. Herein we: show that the natural context to study stochastic integrators and their properties is the convolution shuffle algebra of endomorphisms; establish a new whole class of efficient integrators; and then prove that, within this class, the sinhlog integrator generates the optimal efficient stochastic integrator at all orders.Comment: 19 page

Untangling CP Violation and the Mass Hierarchy in Long Baseline Experiments

In the overlap region, for the normal and inverted hierarchies, of the neutrino-antineutrino bi-probability space for $\nu_\mu \to \nu_e$ appearance, we derive a simple identity between the solutions in the ($\sin^2 2\theta_{13}$, $\sin \delta$) plane for the different hierarchies. The parameter $\sin^2 2\theta_{13}$ sets the scale of the $\nu_\mu \to \nu_e$ appearance probabilities at the atmospheric $\delta m^2_{atm} \approx 2.4 \times 10^{-3}$ eV$^2$ whereas $\sin \delta$ controls the amount of CP violation in the lepton sector. The identity between the solutions is that the difference in the values of $\sin \delta$ for the two hierarchies equals twice the value of $\sqrt{\sin^2 2\theta_{13}}$ divided by the {\it critical} value of $\sqrt{\sin^2 2\theta_{13}}$. We apply this identity to the two proposed long baseline experiments, T2K and NO$\nu$A, and we show how it can be used to provide a simple understanding of when and why fake solutions are excluded when two or more experiments are combined. The identity demonstrates the true complimentarity of T2K and NO$\nu$A.Comment: 15 pages, Latex, 4 postscript figures. Submitted to New Journal of Physics, ``Focus on Neutrino Physics'' issu

Programmable high voltage power supply with regulation confined to the high voltage section

A high voltage power supply in a dc-dc converter configuration includes a pre-regulator which filters and regulates the dc input and drives an oscillator which applies, in turn, a low voltage ac signal to the low side of a step-up high voltage transformer. The high voltage side of the transformer drives a voltage multiplier which provides a stepped up dc voltage to an output filter. The output voltage is sensed by a feedback network which then controls a regulator. Both the input and output of the regulator are on the high voltage side, avoiding isolation problems. The regulator furnishes a portion of the drive to the voltage multiplier, avoiding having a regulator in series with the load with its attendant, relatively high power losses. This power supply is highly regulated, has low power consumption, a low parts count and may be manufactured at low cost. The power supply has a programmability feature that allows for the selection of a large range of output voltages

Neutrino Factories and the "Magic" Baseline

We show that for a neutrino factory baseline of $L \sim 7300 km - 7 600 km$ a ``clean'' measurement of $\sin^2 2 \theta_{13}$ becomes possible, which is almost unaffected by parameter degeneracies. We call this baseline "magic" baseline, because its length only depends on the matter density profile. For a complete analysis, we demonstrate that the combination of the magic baseline with a baseline of 3000 km is the ideal solution to perform equally well for the $\sin^2 2 \theta_{13}$, sign of $\Delta m_{31}^2$, and CP violation sensitivities. Especially, this combination can very successfully resolve parameter degeneracies even below $\sin^2 2 \theta_{13} < 10^{-4}$.Comment: Minor changes, final version to appear in PRD, 4 pages, 3 figures, RevTe

Neutrino oscillation physics with a higher γ\gamma β\beta-beam

The precision measurement and discovery potential of a neutrino factory based on a storage ring of boosted radioactive ions ($\beta$-beam) is re-examined. In contrast with past designs, which assume ion $\gamma$ factors of $\sim 100$ and baselines of L=130 km, we emphasize the advantages of boosting the ions to higher $\gamma$ and increasing the baseline proportionally. In particular, we consider a medium-$\gamma$ scenario ($\gamma \sim 500$, L=730 km) and a high-$\gamma$ scenario ($\gamma \sim 2000$, L = 3000 km).The increase in statistics, which grow linearly with the average beam energy, the ability to exploit the energy dependence of the signal and the sizable matter effects at this longer baseline all increase the discovery potential of such a machine very significantly.Comment: An error corrected, conclusions unchanged. Revised version to appear in Nuclear Physics

Optimal β\beta-beam at the CERN-SPS

A $\beta$-beam with maximum $\gamma=150$ (for \helio ions) or $\gamma=250$ (for \neon) could be achieved at the CERN-SPS. We study the sensitivity to $\theta_{13}$ and $\delta$ of such a beam as function of $\gamma$, optimizing with the baseline constrained to CERN-Frejus (130 km), and also with simultaneous variation of the baseline. These results are compared to the {\it standard} scenario previously considered, with lower $\gamma=60/100$, and also with a higher $\gamma\sim 350$ option that requires a more powerful accelerator. Although higher $\gamma$ is better, loss of sensitivity to $\theta _{13}$ and $\delta$ is most pronounced for $\gamma$ below 100.Comment: 22 page

Physics Potential of Very Intense Conventional Neutrino Beams

The physics potential of high intensity conventional beams is explored. We consider a low energy super beam which could be produced by a proposed new accelerator at CERN, the Super Proton Linac. Water Cherenkov and liquid oil scintillator detectors are studied as possible candidates for a neutrino oscillation experiment which could improve our current knowledge of the atmospheric parameters and measure or severely constrain the parameter connecting the atmospheric and solar realms. It is also shown that a very large water detector could eventually observe leptonic CP violation. The reach of such an experiment to the neutrino mixing parameters would lie in-between the next generation of neutrino experiments (MINOS, OPERA, etc) and a future neutrino factory.Comment: Talk given at the Venice Conference on Neutrino Telescopes, Venice, March, 200

Tribological behavior of functionalized 1-2 layered graphene/uhmwpe composites

In this work we present the evaluation of pristine and functionalized graphene as reinforcements for UHMWPE-based composites. These composites were manufactured by physically blending graphene particles and medical grade UHMWPE powder followed by a thermo-compression process. Mechanical behaviour by means of uniaxial tension and biaxial load by small punch were carried out. Friction coefficient and wear rate were measured. In some cases composites enhanced stiffness and yield stress, although with loss of toughness. This mechanical behaviour was recuperated after a thermal treatment. Small positive changes were obtained with some graphene concentrations respect to the friction coefficient. However, 20 % of reduction in wear rate was obtained when the graphene was functionalized. In general these composites present a good trend to be a potential alternative to the current highly crosslinked polyethylenes.We thank the Ministry of Science and Education of Spain by means of the projects MAT2010-16175) and CONSOLIDER CSD2008-00023 (FUNCOAT) for financial suppor